1. Field of the Invention
The invention relates to coffee makers, and in particular to vacuum type coffee makers.
2. Background Information
A conventional vacuum coffee maker comprises a lower vessel in which water is heated by a burner. An upper vessel is mounted on top of the lower vessel with gasket seal between them. A tube extends between the vessels. The heated water in the lower vessel creates a large amount of steam which forces hot water through the tube to the upper vessel. Coffee grounds in the upper vessel come into contact with the hot water. The burner is stopped when all the water in the lower vessel is forced to the upper vessel. A vacuum is formed inside the lower vessel. As air in the lower vessel cools brewed coffee extracts back from the upper vessel to the lower vessel. This principle of coffee brewing is known as vacuum brew.
The vacuum coffee brewing principle results in an extra hot coffee with very good quality in terms of taste and flavour. The coffee grounds are evenly wet and extracted by hot water. However, the vacuum type coffee brewing principle is not as popular as the drip type coffee maker for the domestic market due to its use of a burner and a more complex, not so user friendly, operation. Typically, it is limited to some niche commercial market segments.
The increasing demand for high quality coffee has resulted in improvements to the vacuum coffee maker to try to make it more marketable to the domestic market. Bodium is one of the pioneers in moving from a burner heater to an electric heater. Bodium uses an electric heating element mounted in the bottom of the lower vessel. However, the Bodium unit has not addressed all of the problems of conventional is vacuum coffee makers. The lower vessel is difficult to clean after use as it cannot be placed in a dishwasher due to the electric heater and an electrical control built into the base of the lower vessel. Furthermore, the handling of the upper vessel with integral tube is a tedious job for the user. The upper vessel is very hot just after the brewing process is complete. The user needs to detach this hot upper vessel from the lower vessel with a tightly sealed gasket. A separate stand is required to hold the detached hot upper vessel, which will occupy and waste some countertop space. The consumer needs to spend a lot of effort before enjoying the cup of coffee from the lower vessel.